Definition: (al-PROSS-ta-dill) One of the drugs known as prostaglandin that causes increased blood flow to certain areas of the body by dilating (opening) the blood vessels. When injected into the penis, it can produce an erection in most cases.

Produced as Caverject by Upjohn and as Edex by Schwarz Pharm. A different delivery of alprostadil is MUSE. See vasodilator.